One nurse had been referred to the Nursing and Midwifery Council over the incident, while others have received retraining and supervision, said the Norfolk, Suffolk and Cambridgeshire Strategic Health Authority.

Thursday's report also criticised a delay of several hours in informing Mr Bennett's family of his death and failing to inform them of the circumstances.

One nurse told a family member he died as a result of breathing difficulties - but a clinical nursing specialist said the family could not be given details of his death because an internal investigation was under way.

The "inhumane" treatment of the family had led them to think there was some kind of a cover-up, the report said.

Norfolk Mental Health Care NHS Trust apologised to Mr Bennett's family and friends, adding that it had "not forgotten that this was a tragedy that happened to a real person".

Neglect

The health authority commissioned the report following a 2002 inquest into Mr Bennett's death in the Norvic Clinic, Norwich.

The inquest jury at King's Lynn, Norfolk, found that he died an accidental death "aggravated by neglect".

Jurors heard he was given unauthorised doses of medication in the days before his death and that nurses used inappropriate restraint procedures.

Jamaican-born Mr Bennett, from Peterborough, Cambridgeshire, had suffered from mental illness since his early 20s.